Well I came across it a few nights ago, its called turntables.fm where you make a room and up to 5 people can play music "taking turns" I was thinking of starting a room for everyone on here for us to listen to all sorts of music from HHN. I'll be creating the room shortly!
There's also not just DJ's in there but there can be tons of people in the room chatting and listening!
Here is the link: http://turntable.fm/halloween_horror_nights_all_years